ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Silenciamiento de genes diana de Delottococcus aberiae DeLotto (Hemiptera: Pseudococcidae) mediante tecnología RNAi
Get PDFEl RNA de interferencia (RNAi) es una de las herramientas biotecnológicas con mayor potencial en la protección de cultivos frente a insectos plagas. Con esta técnica de silenciamiento postranscripcional se puede bloquear la expresión de genes diana de interés al destruir eficazmente su correspondiente RNA mensajero (mRNA). En los últimos años se han logrado avances significativos en varios aspectos del mecanismo de silenciamiento génico postranscripcional mediado por moléculas de RNA de doble cadena (dsRNA). En la actualidad el mundo científico se encuentra en disposición de poder transferir y aplicar de manera práctica esta potente herramienta al control biológico de plagas
Detección y cuantificación del virus del mosaico de la sandía por RT-PCR a tiempo real
Get PDFEl virus del mosaico de la sandía (watermelon mosaic virus, WMV) produce graves daños en varios cultivos de cucurbitáceas en todo el mundo. El control de enfermedades se basa en restringir la propagación del virus y en la obtención de variedades resistentes por mejora genética. Para poder aplicar estas estrategias de control es necesario disponer de herramientas para la detección sensible y la cuantificación precisa de WMV en plantas infectadas. En este trabajo, se desarrolló un procedimiento basado en la retrotranscripción seguida de una PCR a tiempo real con un par de iniciadores y una sonda TaqMan® específicos de WMV
Critical nitrogen dilution curve and dry matter production parameters for several Mediterranean vegetables
Get PDFInadequate nitrogen fertilizing practices lead to low nitrogen uptake efficiency (NUE), which increases water NO3− pollution, as well as N2O emissions to the atmosphere. In order to increase the NUE and decrease the N losses as NO3− and N2O from the soil-plant system, accurate data about optimum crop N concentrations and dry matter production throughout the growing season are still needed for many vegetables typically grown under Mediterranean climate. For this reason, several N fertilization trials were set up for globe artichoke, carrot, cauliflower, chard, chinese cabbage, early potato, leek, lettuce, onion, red cabbage, romanesco, and spinach, under the semiarid Mediterranean conditions of the Valencian Community (Eastern Spain) during several years. The fresh and dry matter weight (W), as well as the nitrogen concentration in the dry matter (%N) in both the marketable and non-marketable crop parts, was measured between 3 and 7 times throughout their respective growing seasons. The a and b coefficients of the average N dilution curve (%N = a W − b), for which all %N and W data were used, and the critical N dilution curve (%Nc = a Wc−b), for which only the minimun %N for maximum W data were used if available, in addition to the dry/fresh yield matter ratio (DM) and the harvest index (HI), were calculated for all these crops. No significant differences were observed between the average and critical N dilution curve coefficients in this work. Interestingly, the coefficients of both N dilution curves differed from the ones found in the literature with the exception of those obtained for similar cultivars, e.g., early potatoes, and under similar climatic conditions, i.e., Mediterranean. Besides, there were neither differences of DM and HI among the several N fertilization treatments. Therefore, due to the absence of changes in the N dilution curve and dry matter production coefficients for the different N supplies, all these parameters were estimated on the basis of the whole dataset, i.e., regardless of the N input. The use of the critical nitrogen dilution curve coefficients and dry matter production parameters presented in this work should contribute to better fit the N fertilizer additions to N demands of these vegetables under Mediterranean conditions, mainly, by their use through simulation models. Therefore, the NUE in horticulture should increase and the N losses as NO3− to inland and sea waters in these environments, and as N2O to the atmosphere should decrease
Pollen Development and Viability in Diploid and Doubled Diploid Citrus Species
Get PDFSeedlessness is one of the most important agronomic traits in mandarins on the fresh fruit market. Creation of triploid plants is an important breeding strategy for development of new commercial varieties of seedless citrus. To this end, one strategy is to perform sexual hybridizations, with tetraploid genotypes as male parents. However, while seed development has been widely studied in citrus, knowledge of key steps such as microsporogenesis and microgametogenesis, is scarce, especially in polyploids. Therefore, we performed a study on the effect of ploidy level on pollen development by including diploid and tetraploid (double diploid) genotypes with different degrees of pollen performance. A comprehensive study on the pollen ontogeny of diploid and doubled diploid “Sanguinelli” blood orange and “Clemenules” clementine was performed, with focus on pollen grain germination in vitro and in planta, morphology of mature pollen grains by scanning electron microscopy (SEM), cytochemical characterization of carbohydrates by periodic acid–Shiff staining, and specific cell wall components revealed by immunolocalization. During microsporogenesis, the main difference between diploid and doubled diploid genotypes was cell area, which was larger in doubled diploid genotypes. However, after increase in size and vacuolization of microspores, but before mitosis I, doubled diploid “Clemenules” clementine showed drastic differences in shape, cell area, and starch hydrolysis, which resulted in shrinkage of pollen grains. The loss of fertility in doubled diploid “Clemenules” clementine is mainly due to lack of carbohydrate accumulation in pollen during microgametogenesis, especially starch content, which led to pollen grain abortion. All these changes make the pollen of this genotype unviable and very difficult to use as a male parent in sexual hybridization with the objective of recovering large progenies of triploid hybrids
Unravelling the Physiological and Genetic Adaptation of Grafted Pepper under Saline and Hydric Stresses
Get PDFPepper culture is economically very important worldwide, although it is very sensitive to suboptimal conditions of water and high salinity. However, the tolerance to these stresses can be improved by the grafting technique. Previous studies of the Valencian Institute for Agricultural Research and the Polytechnic University of Valencia have been conducted to select pepper accessions that showed tolerance to both stresses, after which a further selection of them was used as rootstocks to find physiological mechanisms of tolerance and to increase its agronomic profit. However, after all these studies, the available information in this regard is still scarce. Therefore, the objectives of this thesis were to: I) screen new tolerant pepper accessions under high salt concentrations and suboptimal water conditions, to increase the availability of tolerant genotypes to be used in future breeding programmes, with the final aim of obtaining new and improved tolerant rootstocks; II) identify the short-term physiological mechanisms of water stress tolerance of a tolerant accession (A25) used as a rootstock; III) identify the physiological mechanisms of short-term tolerance to salinity of a new tolerant hybrid rootstock (NIBER®); and IV) find the main molecular pathways of salinity tolerance of a tolerant accession (A25) compared to a sensitive one (A6) by a transcriptomic approach. After conducting these studies, we firstly found a positive relationship between photosynthetic capacity and growth maintenance in plants that were tolerant to water or salt stress, both grafted or ungrafted; indeed, based mainly on this relationship, we selected accessions A34 and A31 as tolerant to salt and water stress, respectively. In addition, we were able to demonstrate that the main role of proline under salinity and water scarcity is not linked herein to the drop in osmotic potential; on the contrary, we identified different
protective roles that, together with other antioxidant protective molecules such as phenols, contribute to the tolerance of pepper plants to these environmental stresses. Moreover, hydrogen peroxide, a reactive oxygen species, was found to play important roles in the antioxidant capacity of pepper, working as a signalling molecule under salinity stress. Furthermore, the drop in abscisic acid concentration and its signalling deregulation were also shown to maintain stomatal aperture and thus the growth of the scion when grafted onto tolerant rootstocks and ungrafted accessions under high salt concentration conditions. It was also demonstrated that a limitation of Na+ transport to leaves, as well as a more efficient transport and accumulation of K+ in roots and leaves, are essential to reach ion homeostasis and, thus, tolerance in pepper plants grafted onto tolerant rootstocks. Finally, the study of the molecular pathways of tolerance was a useful tool to confirm the physiological and agronomical behaviour of a pepper accession previously classified as tolerant, although new mechanisms were also found. The differentially expressed genes found were linked to hormonal signalling, plant growth and development, photoprotection, regulation of ion transporters and ROS detoxification
Estudio agronómico de cultivares de alcachofa (Cynara scolymus L.) procedentes de semilla
Get PDFEl cultivar de alcachofa más cultivado en España es “Blanca de Tudela” multiplicado a través de zuecas o estacas. También se reproduce mediante zueca el cv. Calicó, cultivar tardía de gran calibre destinada al mercado de exportación. En ambos casos se está observando un grave problema de descenso en los rendimientos del cultivo, debido principalmente a marras de plantación y al decaimiento del vigor de las plantas. El objetivo de este trabajo fue estudiar el comportamiento agronómico de cultivares de características similares a las anteriores propagadas por semilla. Se emplearon en el ensayo 10 cultivares de semilla comparándolos con Blanca de Tudela y Calicó multiplicados por zueca, durante la campaña 2016-17, en una parcela experimental en la que se había cultivado alcachofa durante 15 años, con desinfección mediante solarización anual. También estudiamos la influencia que ejerce sobre el ciclo productivo de estas cultivares de semilla la aplicación de ácido giberélico (AG3). De entre los cultivares estudiados, Sambo F1, del tipo “Calicó”, resultó más productivo y precoz que el “Calicó” multiplicado por estaca. Del tipo “Blanca de Tudela” los mejores resultados en cuanto a producción y calidad del capítulo los obtuvo el cv. Symphony F1, de media estación, el cual inicia las recolecciones más tarde y concentra el periodo de recolección en menos tiempo. Entre los del tipo “Imperial Star”, Nova G-6 fue el más productivo, más precoz y con menos trazas violetas en la base del capítulo. De los violetas, el cv. Opera, resultó algo tardío, de color muy atractivo y gran calidad. En general, se ha obtenido una mayor productividad de varios de los cultivares de semilla ensayados respecto a los testigos y una gran influencia sobre la precocidad en la aplicación de ácido giberélico sobre las cultivares más tempranas. Los resultados de estos trabajos confirman que se pueden compensar los problemas de cultivo, que aparecen en suelos donde se reitera la producción de alcachofa, con empleo de los nuevos cultivares y la desinfección de suelos
Evolutionary origin and functional specialization of Dormancy‑Associated MADS box (DAM) proteins in perennial crops
Get PDFBackground: Bud dormancy is a phenological adaptation of temperate perennials that ensures survival under winter temperature conditions by ceasing growth and increasing cold hardiness. SHORT VEGETATIVE PHASE (SVP)-like factors, and particularly a subset of them named DORMANCY-ASSOCIATED MADS-BOX (DAM), are master regulators of bud dormancy in perennials, prominently Rosaceae crops widely adapted to varying environmental conditions. Results: SVP-like proteins from recently sequenced Rosaceae genomes were identifed and characterized using sequence, phylogenetic and synteny analysis tools. SVP-like proteins clustered in three clades (SVP1–3), with known DAM proteins located within SVP2 clade, which also included Arabidopsis AGAMOUS-LIKE 24 (AthAGL24). A more detailed study on these protein sequences led to the identifcation of a 15-amino acid long motif specifc to DAM proteins, which afected protein heteromerization properties by yeast two-hybrid system in peach PpeDAM6, and the unexpected fnding of predicted DAM-like genes in loquat, an evergreen species lacking winter dormancy. DAM gene expression in loquat trees was studied by quantitative PCR, associating with inforescence development and growth in varieties with contrasting fowering behaviour. Conclusions: Phylogenetic, synteny analyses and heterologous overexpression in the model plant Arabidopsis thaliana supported three major conclusions: 1) DAM proteins might have emerged from the SVP2 clade in the Amyg‑daloideae subfamily of Rosaceae; 2) a short DAM-specifc motif afects protein heteromerization, with a likely efect on DAM transcriptional targets and other functional features, providing a sequence signature for the DAM group of dormancy factors; 3) in agreement with other recent studies, DAM associates with inforescence development and growth, independently of the dormancy habit
Transcriptome analysis of the pulp of citrus fruitlets suggests that domestication enhanced growth processes and reduced chemical defenses increasing palatability
Get PDFTo identify key traits brought about by citrus domestication, we have analyzed the transcriptomes of the pulp of developing fruitlets of inedible wild Ichang papeda (Citrus ichangensis), acidic Sun Chu Sha Kat mandarin (C. reticulata) and three palatable segregants of a cross between commercial Clementine (C. x clementina) and W. Murcott (C. x reticulata) mandarins, two pummelo/mandarin admixtures of worldwide distribution. RNA-seq comparison between the wild citrus and the ancestral sour mandarin identified 7267 differentially expressed genes, out of which 2342 were mapped to 117 KEGG pathways. From the remaining genes, a set of 2832 genes was functionally annotated and grouped into 45 user-defined categories. The data suggest that domestication promoted fundamental growth processes to the detriment of the production of chemical defenses, namely, alkaloids, terpenoids, phenylpropanoids, flavonoids, glucosinolates and cyanogenic glucosides. In the papeda, the generation of energy to support a more active secondary metabolism appears to be dependent upon upregulation of glycolysis, fatty acid degradation, Calvin cycle, oxidative phosphorylation, and ATP-citrate lyase and GABA pathways. In the acidic mandarin, downregulation of cytosolic citrate degradation was concomitant with vacuolar citrate accumulation. These changes affected nitrogen and carbon allocation in both species leading to major differences in organoleptic properties since the reduction of unpleasant secondary metabolites increases palatability while acidity reduces acceptability. The comparison between the segregants and the acidic mandarin identified 357 transcripts characterized by the occurrence in the three segregants of additional downregulation of secondary metabolites and basic structural cell wall components. The segregants also showed upregulation of genes involved in the synthesis of methyl anthranilate and furaneol, key substances of pleasant fruity aroma and flavor, and of sugar transporters relevant for sugar accumulation. Transcriptome and qPCR analysis in developing and ripe fruit of a set of genes previously associated with citric acid accumulation, demonstrated that lower acidity is linked to downregulation of these regulatory genes in the segregants. The results suggest that the transition of inedible papeda to sour mandarin implicated drastic gene expression reprograming of pivotal pathways of the primary and secondary metabolism, while palatable mandarins evolved through progressive refining of palatability properties, especially acidity
Memoria actividades 2022
No full textEl IVIA es el lnstituto de lnvestigación e lnnovación Agraria de la Generalitat Valenciana cuya misión es contribuir a la actividad agraria productiva y sostenible, impulsando la competitividad de los sectores agrícola, ganadero y agroalimentario mediante la generación de conocimientos que den respuesta a las demandas técnicas, sociales y económicas, a través de una investigación aplicada y excelente y una óptima transferencia de resultados. El IVIA quiere ser un centro de referencia en investigación agraria, impulsor del desarrollo tecnológico y dinámico en la transferencia de resultados al sector agroalimentario de la Comunitat Valenciana, en cooperación con los agentes de la ciencia, la tecnología y la innovación españolas, europeas y mundiales
Eliciting Plant Defenses Through Herbivore-Induced Plant Volatiles’ Exposure in Sweet Peppers
Get PDFInsect herbivory activates plant defense mechanisms and releases a blend of herbivoreinduced plant volatiles (HIPVs). These volatile compounds may be involved in plant-plant communication and induce defense response in undamaged plants. In this work, we investigated whether the exposure of sweet pepper plants to HIPVs [(Z)-3-hexenol, (Z)- 3-hexenyl acetate, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, hexyl butanoate, methyl salicylate and methyl jasmonate] activates the sweet pepper immune defense system. For this, healthy sweet pepper plants were individually exposed to the each of the above mentioned HIPVs over 48 h. The expression of jasmonic acid and salicylic acid related genes was quantified. Here, we show that all the tested volatiles induced plant defenses by upregulating the jasmonic acid and salicylic acid signaling pathway. Additionally, the response of Frankliniella occidentalis, a key sweet pepper pest, and Orius laevigatus, the main natural enemy of F. occidentalis, to HIPV-exposed sweet pepper plants were studied in a Y-tube olfactometer. Only plants exposed to (Z)-3-hexenyl propanoate and methyl salicylate repelled F. occidentalis whereas O. laevigatus showed a strong preference to plants exposed to (Z)-3-hexenol, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, methyl salicylate and methyl jasmonate. Our results show that HIPVs act as elicitors to sweet pepper plant defenses by enhancing defensive signaling pathways. We anticipate our results to be a starting point for integrating HIPVs-based approaches in sweet pepper pest management systems which may provide a sustainable strategy to manage insect pests in horticultural plants